LeetCode_Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

Note:

All numbers (including target) will be positive integers.
Elements in a combination (a1, a2, � , ak) must be in non-descending order. (ie, a1 ? a2 ? � ? ak).
The solution set must not contain duplicate combinations.
For example, given candidate set 10,1,2,7,6,1,5 and target 8,
A solution set is:
[1, 7]
[1, 2, 5]
[2, 6]
[1, 1, 6]

　　

class Solution {
public:
    void  DFS(vector<int> &candidates, int target, int start, int sum, vector<int> &tp){
    	if(sum == target){
			res.push_back(tp);
			return;
		}
		for(int i = start; i< candidates.size(); ++i){
		    if(i != start && candidates[i] == candidates[i-1])
					continue;
			if(candidates[i] + sum <= target){
				tp.push_back(candidates[i]);
				DFS(candidates, target, i+1, sum+candidates[i], tp);
				tp.pop_back();
			}
		}
	}
    vector<vector<int> > combinationSum2(vector<int> &candidates, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        res.clear();
		int len = candidates.size();
		if(len < 1 || target <1) return res;
		sort(candidates.begin(), candidates.end());
		vector<int> tp;
		DFS(candidates, target, 0, 0, tp);
		return res;

    }
private:
	vector<vector<int>> res;
};